The link between power flow control technologies: Topology control and FACTS

In order to make better use of the existing transmission system, different approaches can be adopted. Previous research shows that both topology control and flexible AC transmission systems (FACTS) can enhance the transfer capability over the existing transmission network and reduce congestion costs. In previous studies, potential cost savings from performing line switching and utilizing FACTS control were investigated separately. This paper studies the interdependence between transmission switching and FACTS device control through integration of both technologies in the optimal power flow (OPF) problem. A comprehensive model for transmission systems with both line switching and FACTS was established; simulation results showed that simultaneous optimization of FACTS set point, FACTS location, and transmission switching would result in a more cost-effective operation than exclusive utilization of each technology. The results also demonstrate that topology control changes the optimal location of the FACTS devices, which is particularly important for the FACTS planning problem.